Windows has a number of mechanisms for programs to start themselves on reboot.

In the startup menu, you can view or execute the shorcuts with:

Click Start

Click All Programs

Click Startup

The short cut files themselves are stored in:
C:\Users\user\AppData\Roaming\Microsoft\Windows\Start Menu\Programs\Startup\
and C:\ProgramData\Microsoft\Windows\Start Menu\Programs\Startup.
You can manipulate them directly with copy/paste/delete.